In the case of a pressure drop in any Fuel Pump, start checking fuel pressure with the aid of a fuel pressure gauge. Generally, on most automobiles, this should not exceed the minimum and maximum pressures of 30 to 60 psi, but some vehicle types may have a higher rating; it will vary based on models and make. For example, a 2018 Honda Civic will run normally with roughly 45 psi whereas other, higher-performance vehicles like a Dodge Challenger might need 55 psi for optimal engine performance. Finally, connect the gauge to the fuel rail test port nearest the engine in order to take a current reading.
Measure the Fuel Pressure of Your Vehicle While the Engine is Running. If you notice a drop of 5 psi or more, it may indicate that the Fuel Pump is having some problems maintaining such pressure. For instance, if the reading of your car runs at a constant 50 psi and suddenly drops down to 40 psi when the car is idling or during acceleration, that’s when you know there’s surely some problem with the pressure. A drop in fuel pressure can, in many ways, emanate from the clogging of a fuel filter or a failing fuel pump since they both are associated with irregularities in fuel flow. While the general tendency is that fuel pumps last between 100,000 to 150,000 miles, debris, poor-quality fuel, or absence of routine maintenance could curtail its lifespan and ultimately cause unstable pressure.
Fuel lines and connections should also be checked for leaks or their conditions. A leaking fuel line will drop the pressure and thus directly impact fuel delivery to the engine. If there are any visible signs of leakage, such as wet spots or fuel odor, replace the damaged section of the line. If the pressure drop persists even after leak checks, then it may be time to clean or replace the Fuel Pump, because a continuous problem of this sort could result in an engine misfire, stalling, or poor acceleration. Normally, a drop of more than 10% below specification is a critical indication that something in the fuel system needs attention.
As an example, in a 2017 Ford Mustang, a drop of more than 10 psi in fuel pressure upon acceleration may lead to engine hesitation or stumble, especially when the load is heavy. The diagnostic tool can also be utilized to see whether the problem is actually with the Fuel Pump or some other component of the fuel system, such as fuel injectors or the pressure regulator. If the problem persists, then one should consult a professional mechanic to ensure proper fuel delivery and avoid further engine damage.